LAS VEGAS -- The pressure of defending his heavyweight title at UFC 100 might be getting to Brock Lesnar.

In the lead up to Saturday's showdown with interim heavyweight champion Frank Mir, Lesnar broke a door after viewing a taped version of their first encounter, which ended when Mir submitted him with a kneebar.

Lesnar has also attempted to dodge the media at every turn. He tried to leave the pre-fight press conference early but UFC president Dana White whispered in his ear, essentially telling him to stick around.

Lesnar has made it clear he doesn't enjoy having the media spotlight focused solely on him. However, he said none of that will matter when he steps into the cage.

"I'm going to leave a lot of emotions out of the octagon that night," Lesnar said. "I'm just going to go in there and stay calm, do what I've been trained to do."

When pressed about the door incident, Lesnar said UFC camera crews merely caught him at a bad time.

"You know, I had just finished working out and I didn't want to be there," he said. "I had to go home and eat, you know. I'm a sore loser and to relive that loss all over again, it was frustrating. The door was just in the way and I was going through it."

Though Lesnar was quick to brush the whole thing off, Mir loved every second of it.

"I really hope it wasn't staged," Mir said. "If it wasn't, I'm really happy about it. If it was, then I'm really disappointed because I hope that stuff stays out of our sport. If he did really break that door, then that's his real personality."

Mir has actively trash-talked Lesnar in the weeks leading up to the fight, the co-main event for the biggest production the UFC has ever staged. The 11-fight spectacle at the Mandalay Bay includes Canadian Georges St-Pierre, the reigning UFC welterwight champ, taking on Thiago Alves and Nova Scotian T.J. Grant facing Dong Hyun Kim in another welterweight bout.

For Mir, a 30-year-old Las Vegas native, getting inside his opponent's head is all part of the strategy.

"Any gorilla can pound somebody's face in, it doesn't take any skill," Mir said. "So physical violence, if that's what you resort to, it's not that impressive. But tactics and mind games, screwing with people, I love that.

"How do you screw with your opponent's head? How do you say certain things? Maybe your opponent has a weak mind and his coaches are keeping him away from you. Now you screw with his coaches. You say bad things about them, like how they don't know how to teach martial arts. I'm saying it right now (about Lesnar's coaches). I have the utmost respect for his coaches. But you have to throw out those little jibs and jabs. Mohammad Ali was a huge advocate of that."

Lesnar, a 31-year-old from South Dakota, laughed off the notion that Mir is inside his head, even complimenting him on some of his insults.

"He's got a pretty sharp tongue on him," Lesnar said. "He had some good stuff, but mine were better."

Lesnar stressed that his loss to Mir in their first fight -- he has complained that a decision by referee Steve Mazzagatti to separate the two grounded fighters and have them resume fighting standing up was a "gift" for Mir and wound up leading to the first-round submission -- doesn't add any additional pressure for the rematch.

"I've been beat before," Lesnar said. "I haven't been beat a lot. I've taken my losses and issued them back to the people that beat me. I've been in this spot before. It's a familiar feeling."

Despite his previous win over Lesnar and his domination of Antonio Rodrigo Nogueira at UFC 92, Mir is considered the underdog going into UFC 100. It's surprising given Mir's edge in experience and 12-3 MMA record.

"I guess I'm going to shave my head and get a lot more tattoos," Mir said. "I actually thought that after the Nogueira fight I wouldn't be the underdog. My friends and I were speaking afterwards about sporting odds. When the odds came out afterwards I was like, ‘S***! Go ahead and bet, guys, because it's good money.

"In terms of why (I'm the underdog), I think people still judge a lot based on potential and humans are visual creatures. If the two of us were standing in a bar, I'd probably pick on me before I pick on him."

One strength Mir feels he possesses over Lesnar is humility.

When his career was sidelined by a horrific motorcycle accident, he had a few lacklustre performances when he returned to the octagon. After some soul searching, he rediscovered his love of martial arts.

Along the way, he even learned to laugh at his poor outings.

"I think when a lot of fighters reach the top of the mountain, the reason they can't hold on to their belts is because they don't have enough humility about themselves," Mir said. "I wish I could have said I got that on my own, but I had to be very humble following the car wreck. My performances kind of sucked.

"The worst thing I can do is have lunch with Joe (Silva, UFC matchmaker) and my wife at the same time. It's one of the most humiliating experiences in the world. You have to have a pretty thick hide at the end of the day and I try not to cry too much."

Comeback or not, Lesnar said he has nothing but disdain for Mir.

"No, I don't have any respect for my opponents," Lesnar said. "As soon as you respect somebody, in my book you're that much closer to getting beat. That's just my philosophy that I've trained by for many years.

"Mr. Mir, I will be seeing you in the octagon Saturday night and I can't wait. I hope you are prepared -- and I know you are."